<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <link rel="stylesheet" href="signal.css">
    <style>
        .box {
            width: 250px;
            height: 52px;
            padding: 15px 30px;
            border: 2px solid #ccc;
            border-radius: 16px;
            margin: 0 auto;
            background-color: #333;
        }
        
        .box .second {
            width: 60px;
            color: #666;
            font-size: 280%;
            line-height: 50px;
            padding-left: 6px;
            margin-left: 5px;
            border: 1px solid #fff
        }
        
        .box div {
            margin-left: 5px;
            float: left;
            width: 50px;
            height: 50px;
            border-radius: 50px;
            border: 1px solid #666;
        }
        
        .box .second {
            border: 0;
            color: #eee;
        }
        
        .off {
            background-color: #eee;
        }
        
        .red {
            background-color: red;
        }
        
        .yellow {
            background-color: yellow;
        }
        
        .green {
            background-color: #26ff00;
        }
    </style>
</head>

<body>
    <div class="box">
        <div id="red"></div>
        <div id="yellow"></div>
        <div id="green"></div>
        <div class="second" id="second"></div>
    </div>
    <script>
        var red = document.querySelector('red');
        var yellow = document.querySelector('yellow');
        var green = document.querySelector('green');
    </script>
</body>

</html>